NUCMED - MIDTERM L1 Flashcards
Physical characteristics should be observed for any radiopharmaceutical for the _____ and ______ use
First and Frequent
________ should be identified for both true solution and ___________
- Color Alterations
- Colloidal Preparations
True solutions should also be checked for ______ and presence of any particulate matter
Turbidity
Radionuclidic Purity is also defined as the ______ of the total radioactivity present as the stated radionuclide.
Proportion
Refers to the presence of radionuclides other than the one of
interest
Radionuclidic Purity
Radionuclidic Purity can be determined by measuring the _____ and _____ emitted by each radionuclide
- Half - lives
- Characteristic Radiations
Image quality and radiation absorbed dose are _______ to the radiochemical purity
Directly Related
The proportion of the stated radionuclide that is present in the stated chemical form
Radiochemical Purity
It is time dependent on exposure to light, change in temperature, and radiolysis, and the longer the time of exposure is, the higher the probability of decomposition will be.
Stability of a Compound
Method of separating a radiochemical form from another with an appropriate chemical reagent
Precipitation
Performed simply by passing a radiopharmaceutical sample through a column of ionic resin and eluting the column with a suitable solvent.
Ion Exchange
Method applicable to compounds with different vapor pressures
Distillation
How many compounds can be separated by simple distillation at a specific temperature ?
Two (2)
The property of charged
molecules (atoms) to migrate in an electric field
Electrophoresis
Which sterility biological test is performed for short-lived radiopharmaceuticals ?
Membrane Filtration
It is dependent on the charge and size of the molecule.
Migration Rate
The apparatus used in electrophoresis consists simply of a direct current power supply to provide a potential difference of _______
400 V or Greater
The 400 V DC Power Supply for Electrophoresis is connected through an _________ to either end of a strip of support medium
Electrolyte Buffer Solution
Which sterility biological test is performed for long-lived radiopharmaceuticals ?
Autoclaving
Its objective is to ensure that the sterilization processes are conducted properly
Sterility
Pyrogenicity is developed from the _________
Rabbit Test
A proper sterility test involves the incubation of the
radiopharmaceutical sample for _____ days
14
It is the incubation medium for growth of AEROBIC and ANAEROBIC BACTERIA
Fluid Thioglycollate Medium
It is the incubation medium for growth of FUNGI and MOLDS
Soybean-casein Digest Medium
They produce symptoms of fever, chills, malaise, joint pain, sweating, headache, and dilation of the pupils within 30 min to 2h
after administration.
Pyrogens
This should be applied for all radiopharmaceuticals approved for human use
Toxicity
It is a quantity that describes the toxic effect of a radiopharmaceutical by determination of the dose required to produce mortality of 50 % of a specifies in 60 days after administration of a radiopharmaceutical dose
LD50/60
It is the earliest means of capturing any sort of data from radioactivity
Photographic Plate
When a photographic plate is developed, it would have ____ or be _____ from the exposure to the radiation
- Spots
- Fogged
This uses a pair of gold leaves that would become charged by the ionization caused by radiation and repel each other.
Electroscope
Ionization Chambers are also valuable for the measurement of ________, as they do not have any of the issues with dead time that other detector types can have
High-energy Gamma Rays
This is the first type of radiation detector wherein gas in the detector meets radiation and is followed by a certain reaction where the gas becomes ionized and the resulting electronic charge being measured by a meter.
Gas-Filled Detectors
They operate at a low voltage, meaning that the detector only
registers a measurement from the “primary” ions caused by an
interaction with a radioactive photon in the reaction chamber.
Ionization Chambers
Ionization chambers cannot be used for which procedure for they are unable to discriminate between different types of radiation
Spectroscopy
Generaly devised so that for much of the area inside the chamber,
they perform similarly to an ion chamber, in that interactions with
radiation create ion pairs.
Proportional Counter
As the ions approach the detector anode, the voltage increases,
until they reach a point where a _______ effect occurs
Gas Amplification
Proportional Counters have a strong enough voltage that the ions ____ towards the detector anode
Drift
Operating at a much higher voltage than other detector types, they
differ from other detector types in that each ionization reaction,
regardless of whether it is a single particle interaction or a stronger
field, causes a gas-amplification effect across the entire length of
the detector anode.
Geiger-Muller Counter
Generally using a semiconductor material such as silicon, they
operate much like an ion chamber, simply at a much sma ler scale,
and at a much lower voltage.
Solid State Detectors
These are materials that have a high resistance to
electronic current, but not as high a resistance as an insulator.
Semiconductors
Solid State Detectors are composed of a _____ of atoms that contain _______
- Lattice
- Charge Carriers
A general term referring to the process of giving
o f light.
Scintillation
Any material that can release a photon in the
UV or visible-light range, when an excited electron
returns to its ground state.
Scintillator
The scintillators used in nuclear medicine applications are _________
Inorganic Crystalline Scintillators
[Nal(Tl)] was developed for use in radiation detection by ________ in _____
- Robert Hofstadter
- 1948
Most common
inorganic scintillator employed in nuclear medicine
Thallium-Activated Sodium Iodide [Nal(Tl)]
GAMMA CAMERA SYSTEMS
Defines lines of response
Collimator
Lead (Pb) possesses the following quantitative properties:
- High Atomic Number =
- High Density =
- Mass Absorption Coefficient =
- High Atomic Number = 82
- High Density = 11.3 g/cm3
- Mass Absorption Coefficient = 2.2 cm2/g at 140 keV associated with Tc-99m emission
GAMMA CAMERA SYSTEMS
Counts the incident gamma photons
Radiation Detector
GAMMA CAMERA SYSTEMS
It supports and moves gamma camera and patient
Gantry System
A multi-hole aperture which collects and outlines radioactivity distributed within different tissues.
Collimator
GAMMA CAMERA SYSTEMS
Creates 2D Images from Detector Data
Computer System
TYPE OF COLLIMATOR:
Most frequent geometry, 1:1 ratio between object and image size
Parallel Collimator
The collimator material is often made of ____ due to its attenuation
and absorption properties.
Lead
Gamma radiation emitted from a radioactive source are uniformly
distributed over a _______
Spherical Geometry
What are the four types of collimators:
- Parallel
- Converging
- Diverging
- Pinhole
(POST-CONCERT-DEPRESSION-PO)
TYPE OF COLLIMATOR:
Image magnification, used to image small organs
Converging Collimator
TYPE OF COLLIMATOR:
This is used to image large objects in small field of view camera
Diverging Collimator
TYPE OF COLLIMATOR:
Focal point between image plane and object being imaged
Pinhole Collimator
Its holes and septa are parallel to
each other, providing a chance for those photons that fall
perpendicular to the crystal surface to be accepted.
Parallel-Hole Collimators
The image size projected by the parallel-hole co limator onto the
crystal is _____
1:1
They provide a small acceptance angle by the aid of their narrow and
longer holes, helping resolve fine details and improve the spatial resolution of the acquired images
Lehr Collimators
Medium-energy radionuclides such as _______ and _______ and High-energy radionuclides such as _____ and _______ have high penetrating power
ME Collimators
1. Gallium-67
2. Indium-111
HE Collimators
3. Iodine-131
4.Fluorodeoxyglucose-F18 (FDG)
They have increased septal thickness and provide a lower
transparency to high-energy gamma photons than lower-energy
collimators
ME & HE Collimators
Have a smaller field of view, whereas the diverging ones offer a larger field of view than that provided by parallel-hole collimators.
Converging Collimators
What are the two (2) special types of gamma camera collimator:
- Cone Beam
- Fan Beam
It has one focal point for all collimator holes that lies
at a certain distance away from the collimator surface and is called
the focal point
Cone Beam
The direction of the holes diverges from the point of view of the back surface of the collimator.
Diverging Collimators
Each row of collimator
holes has its own focal point, and
a l the focal points form a focal line
for the entire co llimator.
Fan Beam
The second component that encounters the incident photons after passing the collimator holes
Scintillation Crystal
It is a cone shaped structure made of lead, tungsten, and platinum and has
an aperture of a few millimeters in diameter (2 6 mm), important for nuclear medicine especially in SMALL-ORGAN imaging.
Pinhole Collimators
Nal(Tl) Crystal must be sealed in an ____, usually ______
- Airtight Enclosure
- Aluminum
Scintillators of the following characteristics are desired and allow better imaging performance (5):
- High Density
- High Atomic Number
- Short Decay Time
- High Light Output
- Low Cost
_______ of the scintillation crystal allows the spatial
resolution of the imaging system to be improved to an extent determined mainly by the segmentation size
Segmentation
The addition of _____ makes the NaI crystal scintillate at room temperature since pure a NaI
crystal works at a low temperature under nitrogen cooling
Thallium
Exposing Nal(Tl) Crystal to air can cause _______
Yellow Spots
An electrode that
collects the amplified electrons through the
multistage dynodes and outputs the electron
current to an external circuit.
Anode of the Photomultiplier Tube
It is an important hardware component in the
detection system of the gamma camera with a main function of converting scintillation photons to a detectable electronic signal
Photomultiplier Tube
It is a photo-emissive surface usua ly consisting of bi
alkali metals with low work functions and weakly bound
valence electrons.
Photocathode
Denotes the decay time of the scintillation event within the crystal, and the decaying tail denotes the time taken by the electrons to traverse the PMT.
Rapid Peak
The signal produced from the PMT has a high impedance value, and this
requires matching with the other electronic circuit components,
Matching
The signal that is to be fed into a main amplifier needs to have a certain pulse
decrease time to a low proper pole-zero and baseline correction.
Shaping
The amplifier is specifically called as ________
Shaping Amplifier
Is required to
permit further processing by the rest of
the detector electronics.
Signal Amplification
Its function is to shape the pulse, decrease resolving time, provide higher gain, and provide stability to maintain proportionality between pulse height and photon energy deposition in the crystal.
Amplifier
Measures the energy spectrum as a function of position in the image using a source or sources with known energies
Typical Energy Correction Algorithm
Are needed because of biases in estimated
interaction positions
Spatial Corrections
It is a device that that can measure the amplitude pulse heights and compare them to preset values stored within it
Pulse Height Analyzer
These are corrections that involve imaging a mask with a grid of holes or lines in combination with a flood source, needed because of biases in estimated interaction positions
Spatial Corrections
The goal of this correction is to make images of a flood source as uniform as possible
Uniformity Corrections
Are usually acquired using a point source containing a small quantity of the isotope of interest
Intrinsic Flood Images
Are made using a flood or sheet source as fillable flood sources that have the advantage that they can be used for any isotope
Extrinsic Flood Images
Refers to building spatial histograms of the counts as a function of position and possibly other variables
Image Framing
They typically offer the ability to simultaneously frame images corresponding to more than one energy window
Image Framing
It provides radiation shielding for detectors and magnetic shielding for the PMTs, incorporating a temperature control system and a mounting for collimators
Camera Housing
He is the inventor of MULTIMODALITY MEDICAL IMAGING TECHNIQUES who opened a gate to many applications in the field of diagnostic radiology and nuclear medicine by coupling two imaging techniques into one operating device.
Bruce Hasegawa
The SPECT Camera has been merged to ________ in the same device to provide an inherent anatomolecular imaging modality able to depict morphological as well as functional changes in one imaging session
X-ray Computed Tomography (CT)
SPECT/CT provides a resolution in the _______ range
Submillimeter
This has been shown to outperform radionuclide-based transmission scanning by providing fast and significantly less noisy attenuation maps
CT-based Attenuation Correction
SPECT/CT lacks the property of describing the _______ of a disease.
Functional Status
He predicted the existence of Positron
Paul Dirac (1928)
To whom did Dirac share the Nobel Prize with and in what year ?
Erwin Schrodinger (1953)
He observed positrons in cosmic rays
Carl Anderson (1932)
To whom did Anderson share the Nobel Prize with and in what year ?
Victor Hess (1936)
It is one of the antimatter physical particles that has a short lifetime and decays quickly by combining with a surrounding electron to release two 511-keV photons in a back-to-back collision process
Positron
The most widely used positron emitter that has a well-defined radiochemistry, and labeling with various biomolecules continuously advancing to suit specific target issues.
Fluorine-18
It means “outside the body”
Bonus Q: Give an example of In-Vitro Nuclear Medicine.
In Vitro
Ex: Gamma Counter
It is considered the gold standard method to determine thyroid hormone levels because it exhibits high sensitivity and specificity and low detection limits.
Radioimmunoasay (RIA)
What is measured and is considered as the best way to initially test thyroid function ?
Thyroid Stimulating Hormone (TSH)
Fill in the Blanks:
High TSH Level =
Low TSH Level =
High TSH Level = The Thyroid Gland is NOT MAKING ENOUGH THYROID HORMONE
Low TSH Level = The Thyroid is producing TOO MUCH THYROID HORMONE
Affected by medications and medical conditions that change thyroid hormone binding proteins
FT4 - Free Thyroxine
What are the common causes of increased thyroid hormone binding proteins (5):
- Estrogen
- Oral Contraceptive Pills
- Pregnancy
- Liver Disease
- Hepatitis C Virus Infection
What are the common causes of decreased thyroid hormone binding proteins (2):
- Testosterone / Androgens
- Anabolic Steroids
It is possible but is often not reliable and therefore may not be helpful, but is used to support a diagnosis of hyperthyroidism and can determine the severity
FT3 - Free Triiodothyronine
Hyperthyroid patients typically have an ___________
Elevated Total T3 Level
It means “inside the body”
In-Vivo
It is the storage area for Nuclear Medicine Radiopharmaceuticals
Hot Lab
This is the container of radiopharmaceuticals
Lead Pig
This is where the radiopharamaceuticals are dispensed
L-Shield
It gives the measurement of the activity contained by the radiopharmaceutical
Dose Calibrator
It detects radioactivity coming from the patient and converts radiant energy into an electronic signal to form an image
Radiation Detectors
It functions to support the radiation detectors
Gantry
